Improvement in cranes



UNITED STATES PATENT OFFICE.

lBENAJAII J. BURNETT, OF MOUNT VERNON, NEW YORK.

IMPROVEMENT IN CRANES.

Specification forming part of Letters Patent No. 46,2 13, dated February7, 1865.

To all whom it may concern.-

Be it known that I, BENAJAH J. BURNETT,

han) ing drawings, iorming partof this speci.

ication, in which- Figure l is a side elevation of a crane with myimInOvements, with part of the traveling roller frame in section. Fig. 2is a plan of the same. Fig. 3 is a vertical section oi' the supportingtower or column and counter-weight frame.

bimilar letters of reference indicate corresponding parts in the severalfigures.

This invention relates to cranes in which the whole. weight of the `jiband the body to be lifted is received on top ot' a supporting tower orcolumn, around which the jib is capable of revolving.

lt consists in an improved construction of this tower of cast-iron;also, in an improvement in the construction of and mode of or head, andby which the horizontal thrustY of the lower part of the jib istransmitted to the lower part of the tower or column; and it,

further consists in an improved method of suspending the traveler fromthe said revolving cap or head. These improvements enable the crane tobe made of the necessary strength and stability to be given to it with aless weight of material, its construction to be simplified and thefriction of its parts reduced in the swinging of the jib around thetower or column.

To enable others skilled in the art to construct a crane according` tomy invention, I will proceed to describe it with reference to thedrawings.

A is the supporting tower or column, constructed of cast-iron, hollow,and in one or more pieces in height, with a bottom horizontal flange, a,forming a base on which are bosses b b for the reception of holding-downbolts, the said bosses being connected bv ribs c c with the tower andiiange. The lower part of this tower or column is formed with a verticalcylindrical surface, d, concentric with its axis, to form a bearing forthe vertical antifriction rollers c e of the circular traveler B, astbesaidtraveler revolves around the tower, and a square shoulder, j', isformed on the tower or column above this vertical cylindi ical surfacefor the support of the upper ring, g, of the frame which contains thesaid antifriction rollers. The top of the tower or column is made with asurrounding flange or protuberance, h, to give it the necessary strengthof metal to enable the formation within it of a circular seat for thefixed wrought-iron or steel ring, t', in which work the anti-frictionballs j j, which support the cap or revolving head U, from which theweight ofthe jib and other revolving parts of the crane are suspended.

The cap or revolving head O is of castiron or other metal, having a iiatbase with ribs or inverted brackets k k, for the necessary sheave andtension bar pins l m, beveled bosses y y for the reception of thecounterweight tension-rods D D, side hubs, n n, for the branch siderods, G q q q, a rib, n', connecting the latter bosses across the centerof the cap, and a central downwardly-projecting journal, p, which entersthe circular box in which the balls j j work, the said journal receivingupon and having attached firmly to it the revolving wrought-iron or'steel ring i', which combines with the lower ring, z', before mentioned,to form an annular box in which the anti-friction balls jj work. Thering t' is of such angular or other form in its transverse section as toform the bottom and the outer sides ofthe said box, and the ring i is ofsuch angular or other form in its transverse section as to form the topand inner sides of said box. This box, while the rollers t in suchmanner as to be capable of revolving freely within it, has its annularcavity of such width as to prevent any movement of the cap except itsrevolution.

The circular traveler B is constructed with v a ange, B', to receive thebranch side rods q q q, and with seats r s, for the reception of thelower ends of the jib-sheets E E and counter-weight sills F F, eachacting against the other. The jib-sheets are furnished with shoes t,which form rolling joints in the seats r, to admit ot' the raising` andlowering of the jibhead, and which are held in place by lippins t.

The branch side rods on each side of the column are made single at thetop, as shown at G in Fig. l, to pass through the side hubs, n it, ofthe cap or revolving head C, above which they are secured by screws andnuts n2 n2, and with two or more branches, q q q, diverging toward thebottom and secured at their lower ends to the circular traveler B byscrews and nuts u u below the iiaiige B ot' the traveler.

Tllejib-head is connected with the cap or revolving head C by means ot'two sets of tens'on-bars, H H and I I, the latter attached by the pin mto the cap or revolving head, and the former by a pin, v, to thejib-head, and

Vthe two sets being connected together by pulleys u w and a tackle,@which serves to raise alid lower the jib-head, as ina-y be required.

What I claiin as 1ny invention, and desire to secure by Letters Patent,is-

l. The castiron tower or column, ot' one or more pieces in height, withbottom iiange or base, a, vertical cylindrical surlace d, and shoulderf, all substantially as and forthe purpose herein specied.

2. The construction of the topot' the said tower, substantially asherein described7 with a seat in its interior for the reception of thelower ring, t', of the box which contains the anti-friction balls, uponwhich the cap or revolving head. of the crane is supported.

3. The cast-metal cab or revolving head C,

provided with ribs or inverted brackets 7c it, for the reception of thesheave and tension bar pins Z m, and central vdownwardlyprojectingjonrnal p, entering the box which receives the anti-frictionballs upon which the said cap or head is supported, and receiving uponit the upper ring, t, of the said box, all substantially as hereinspecified.

4. The annular box for the reception of the anti friction balls whichsupport the cap or revolving head C, constructed of two rings, i, i',the one forming the bottom and outer sides of the box, iitted into asea-t in the top of the tower or column, and the other forming the topand inner sides ot' the box, fitted to the journal ot the cap orrevolving head, substantially as herein described.

5. The construction ot' the circular traveler B, with a ilange for thereception of the sus'- pending side branch rods, and with bearings forthe reception ot the jib shoes and counterweight sills, so that eachthrusts against the other, and a rolling joint is provided for the saidshoes to permit the adjustment ofthe jib, all substantially as hereinset forth.

6. The branch side rods for suspending the circular traveler from therevolving head or cap, constructed with theirnpper parts single, asshown at Gr, and with their lower parts in two or more branches, asshown at g qq in Fig. l, and combined with the cap or revolving head andtraveler, substantially as herein de scribed.

BENA JAH J. Y BURNETT.

Witnesses:

J. W. CooMBs, HENRY T. Bao WN.

